It was a unit used in measuring the 1.8kV in E. coli. The energy is in wastewater.
Mitochondria is a very thin layer, film, or basically on the cellular level.
It is an apples-to-oranges comparison. I have never sat down to rework such a comparison.
Imagine a reservoir of wastewater above ground or underground that gives us electricity. Being on the cellular level is unnecessary when you think of scaling up the source.
Curious idea, there are oceans down in the earth’s mantel. I wonder if any of them have a charge.